docs: def cont_r(self, percent=0.9, N=None):
  		"""Return the contribution of each row."""
  
  		if not hasattr(self, 'F'):
  			self.fs_r(N=self.rank)  # generate F
  		return apply_along_axis(lambda _: _/self.L[:N], 1,
  			   apply_along_axis(lambda _: _*self.r, 0, self.F[:, :N]**2))